If the engine was running OK, but the car wasn't accelerating, I seriously doubt there was bad gas. Was the engine coughing and sputtering, stalling and being hard to start, sure...maybe bad gas. But even then, maybe lots of other things.
IF you had some of that previous "bad gas", and had it tested ($$), then maybe you would have recourse against the gas station, but it would cost you to go after them. Even if you won, the amount of time and energy expended may not be worth the end result.
You could try and find multiple people who had similar experience at the same station. If they were distributing bad fuel, a lot more than just you would have gotten some.
If you would like to post lots more information on how the car is actually running, we can probably have a decent shot at figuring it out, or give you advice on what to test next.
Good luck with whatever course you choose.